Which of the following are the major targets of growth hormone?

• A. Kidneys and adrenal glands
• B. Heart and lungs
• C. Liver and pancreas
• D. Bones and skeletal muscles

Answer: (D)

Verified step by step guidance

1. Understand the role of growth hormone (GH): Growth hormone is a peptide hormone secreted by the anterior pituitary gland. Its primary function is to stimulate growth, cell reproduction, and regeneration in the body.
2. Identify the major targets of growth hormone: GH primarily targets tissues that are involved in growth and development, specifically bones and skeletal muscles. These tissues respond to GH by increasing protein synthesis and promoting cell division.
3. Explain the mechanism of action: Growth hormone stimulates the liver to produce insulin-like growth factor 1 (IGF-1), which plays a key role in promoting the growth of bones and skeletal muscles. IGF-1 enhances the proliferation of chondrocytes (cartilage cells) and osteoblasts (bone-forming cells), leading to bone growth.
4. Differentiate from other organs: While GH has some effects on other organs like the liver and pancreas, its major targets are bones and skeletal muscles because these are the primary tissues involved in physical growth and development during childhood and adolescence.
5. Conclude with the correct answer: Based on the physiological role of growth hormone, the major targets are bones and skeletal muscles, as these tissues are directly influenced by GH to promote growth and development.